Ernst-August Seyfarth

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Sensitive hearing organs often employ nonlinear mechanical sound processing which generates distortion-product otoacoustic emissions (DPOAE). Such emissions are also recordable from tympanal organs of insects. In vertebrates (including humans), otoacoustic emissions are considered by-products of active sound amplification through specialized sensory(More)
Two types of sensory organs in crustaceans and arachnids, the various mechanoreceptors of spiders and the crustacean muscle receptor organs (MRO), receive extensive efferent synaptic innervation in the periphery. Although the two sensory systems are quite different-the MRO is a muscle stretch receptor while most spider mechanoreceptors are cuticular(More)
Spider mechanosensory neurons receive an extensive network of efferent synapses onto their sensory dendrites, somata and distal axonal regions. The function of these synapses is unknown. Peripheral synapses are also found on crustacean stretch-receptor neurons but not on mechanosensory afferents of other species, although inhibitory GABAergic synapses are a(More)
The tympanal organ of the bushcricket Mecopoda elongata emits pronounced distortion-product otoacoustic emissions (DPOAEs). Their characteristics are comparable to those measured in other insects, such as locusts and moths, with the 2f1-f2 emission being the most prominent one. Yet the site of their generation is still unclear. The spatial separation(More)
This review focuses on the structure and function of a single mechanoreceptor organ in the cuticle of spiders. Knowledge emerging from the study of this organ promises to yield general principles that can be applied to mechanosensation in a wide range of animal systems. The lyriform slit sense organ on the antero-lateral leg patella of the spider Cupiennius(More)
Here we describe the neuronal organization of the arcuate body in the brain of the wandering spider Cupiennius salei. The internal anatomy of this major brain center is analyzed in detail based on allatostatin-, proctolin-, and crustacean cardioactive peptide (CCAP)-immunohistochemistry. Prominent neuronal features are demonstrated in graphic(More)
Sensitive hearing organs often employ nonlinear mechanical sound processing which produces distortion-product otoacoustic emissions. Such emissions are also recorded from insect tympanal organs. Here we report high frequency distortion-product emissions, evoked by stimulus frequencies up to 95 kHz, from the tympanal organ of a notodontid moth, Ptilodon(More)
Tympanal organs of insects emit distortion-product otoacoustic emissions (DPOAEs) that are indicative of nonlinear ear mechanics. Our study sought (1) to define constraints of DPOAE generation in the ear of Locusta migratoria, and (2) to identify the sensory structures involved. We selectively destroyed the connection between the (peripheral) sensory(More)
Over the past 76 years Alberto Stefanelli has successfully used a comparative approach to study the nervous system. His main research focus during that time has been on identifiable reticulospinal neurons including Müller and Mauthner neurons found in anamniotic vertebrates. Born in Venice, Italy in 1908, Professor Stefanelli pursued most of his academic(More)
Johann H.L. Flögel (1834-1918) was an amateur scientist and self-taught microscopist in Germany who 130years ago pioneered comparative arthropod neuroanatomy. He was fascinated by innovations in optical instrumentation, and his meticulous studies of the insect supraoesophageal ganglia were the first to use serial sections and photomicrographs to(More)